[백준 1753]최단 경로

https://www.acmicpc.net/problem/1753

1753번: 최단경로

 

요구사항

1. 각 정점까지의 최소거리

 

풀이

1. 다익스트라 기본 문제

 

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

struct go {
    int x;
    int y;
};
int dist[300001];
int n,m;
int startnode;
vector<go> v[20001];
int main(){
    cin>>n>>m;
    cin>>startnode;
    for(int i=0 ; i < m ; i++){
        int x,y,z;
        scanf("%d%d%d",&x,&y,&z);
        v[x].push_back({y,z});
    }
    priority_queue<pair<int,int>> q;
    q.push({0,startnode});
    for(int i=1; i<=n ; i++){
        dist[i]=987654321;
    }
    dist[startnode]=0;

    while(!q.empty()){
        int cost = -q.top().first;
        int node = q.top().second;
        q.pop();
        for(int i=0 ; i <v[node].size();i++){
            int next=v[node][i].x;
            int c = cost +v[node][i].y;
            if(dist[next]>c){
                dist[next]=c;
                q.push({-c,next});
            }
        }
    }

    for(int i=1; i<=n ; i++)
    {
        if(dist[i]==987654321){
            printf("INF\n");
        }
        else{
            printf("%d\n",dist[i]);
        }
        
    }

}